Estes Saturn 1B, #7251 Build, Part 8, Adhering Low Wrap

The 3M 77 adhesive will hold the wrap down, but the joint seams can lift.

I squeezed a drop of medium CA glue onto some scrap cardboard. A toothpick was dipped into the CA glue and transferred, directed down the seam edge. 

Immediately (before the CA glue can set up) a burnisher was pressed down the seam to seat the edges.

The butt joint seam is sanded with 400 grit wrapped around a soft cotton Q-tip. This gives you cushioned sanding.

A fin will be glued over and cover most of the seam. Pay attention to the low end of the seam which you can see on the finished model.

With the wrap lined up with the top of the body tube, there might be a little overhand on the back.

This was trimmed off with a sharp knife, then sanded flush with a sanding block. 

Build time:

Adhere Low Wrap: 20 minutes

Total build time so far: 6 hours, 5 minutes

Estes Saturn 1B, #7251 Build, Part 7, Fitting Low Wrap

The instructions say to trim off the bottom of the lower, narrower wrap to 1/32" below the corrugations.

The top picture is the before - I've marked the 1/32" cut with pencil lines.

Below is after the cut. Use a straightedge and a new, sharp knife blade. 

The ends are trimmed to 3/16" from the start of the corrugations. I left mine long before marking the butt joint with pencil.

The first cuts are long, a slight overlap still exists. 

I'd rather sand the edges to size with a sanding block until the ends meet up.

The wrap is flipped over and taped down to a piece of scrap cardboard for a spray of "77" adhesive. In the picture, under the wrap - Roll tape into a small loop, sticky side out.

I prefer the 3M 77 spray. It allows for lifts and repositioning before a more permanent bond sets in. Chances are very good you will need to lift the wrap and try a second time to get it to match up at the joint ends.

EDIT: Before using any adhesive (Spray adhesive or Super Glues (CA glue) on a vacu-form wrap, check to be sure it is compatible. Save some of the border scraps and test first!  

Build time:

Fit Low Wrap: 20 minutes

Total build time so far: 5 hours, 45 minutes

Centuri Vector V #KB-2 Build, Part 8, Coolant Vane Base

In the original kit, Centuri had you cut the vane coolant pattern off the thin 20 lb. paper instruction sheet. I wanted a little more visual relief so it was redrawn to fit the BT-20 and printed on 110 lb. card stock.

I pre-curled the pattern. Even though it is flattened out for the adhesive spray, the pre-curl will help the fit of the wrap.



From the Centuri instructions:
This shows the possibilities with the four different root edge choices and different placements of the coolant vane pieces.

Plan ahead for your favorite look.

The vane pattern pieces were taped print side down on scrap cardboard.

You could use a thin coat of glue, but might end up with some wrinkling.
I used the Scotch Super 77, the same stuff used on the Saturn V vacu-form wraps. The back side was lightly sprayed.





I'm building two different Vector Vs, one with the coolant vane position at the top, the second almost at the bottom of the 6" BT-20 tube.






As usual with the Super 77 adhesive, the ends can lift.
A small bit of glue was sneaked in on a knife blade.
The ends are burnished down with the back end of a Sharpie barrel.

Estes Saturn V #1969 Build, Part 14, Gluing the Vacu-Form Wraps

I would recommend the Scotch 77 spray adhesive to attach the wraps. It does come in different looking cans.
The "45" adhesive is meant for lighter applications, like mounting a photo in an album.
"77" is a mid grade adhesive and allows for re-positioning. Trust me - You will probably be lifting and re-positioning these. You'll have about 10 minutes of working time before the adhesive starts to dry.
The "90" adhesive will certainly work, but really grabs! You could have trouble trying to lift and realign the wraps. The 90 formula comes out like a spider web. The thickness of the spray may change the wrap fit on the body tube.

TIP: Spray and place only one wrap at a time! If you were to spray them all at once, the upper wraps would be dry by the time you get around to them.

Tape rolls were set on the outside of the wrap, the side that will show on the model. Flip over the wrap and stick the tape rolls on a piece of cardboard.

Spray the adhesive on some scrap cardboard to check width and density of the spray.
Spray the adhesive directly over the top of the wrap back, not at an angle. You don't want any spray on the underside face of the wrap. You will probably get a bit of adhesive on the edges. You'll notice that when you are handling the wrap.
Be sure the sides (left and right side near the butt joint) get sprayed.

TIP: Before setting down the lowest fin area wrap, double check the directions of the corrugations. This lowest wrap is an easy one to set upside down.
The left edge of this first wrap goes down the pencil line you drew down the body tube at the start of the build.
Set down the wrap, don't press to adhere it yet. After getting back to the start point, see how it matches up. Lift and re-position until the end of the wrap is matched with the start with no "step" at the ends. On the last re-position, pull on the end as you roll it down to get rid of any raised areas at the top and bottom. 

You will probably have some end lifts after the wrap has sat for an hour. Hold down the end and "sneak" some thin CA glue on the seam. Do an inch at a time.
Have Q-tips and paper towels handy to pick up any excess CA glue before it dries.

You can carefully size the wraps and you might still end up with a gap. The spray adhesive might add some diameter thickness to the wrap.

I mentioned to save those thin plastic trimmed strips. Find one that'll friction fit into the gap.

The fill strip will want to move around so position and apply the brush on glue about an inch at a time.
Brush on the glue, wipe off the excess with a Q-tip.
Fold up a piece of sandpaper and clean up the filled corrugation.

Each wrap takes about 15 minutes to spray and position on the model.
Four wraps on the lower body = 1 hour. Filling the edge gaps on two wraps 30 minutes.

Assembly time so far:
 6:30 minutes previous
 1:30 minutes gluing four wraps on lower body - this post
 8:00 hours total

Estes Little Joe II (Small) Build, Part 13, Kevlar and Wrap

The engine mount has already been glued into the body tube. I probably should have tied the Kevlar loop, fitted to the BT-5 engine mount tube.

To do it after the fact,
The Kevlar I'm using has started to unravel. Some glue was applied on the last inch and a half. Twist the Kevlar as you rub the glue into the fiber winds. This stiffens the line and allows you to tie it and feed the loose end through the interior tube.

I couldn't tie the tube loop with the mount already glued in so it was tied around a scrap piece of BT-5. Tie it fairly tight but give the loop a little slack so the engine hook can have movement.

The loose end is fed through the tube and the loop fitted around the short extension of the engine mount tube. Long tweezers can help fit the loop.

The corrugated wrap is slightly formed in the palm of my hand with a 1/2" diameter dowel. Concentrate on the ends so they curve and meet at the tube joint.

Make two small tape loops with the adhesive side out. You don't want it too sticky, it could peel up a layer of paper when it's pulled off.
Before setting on the finish, corrugated side, press and peel off your pant leg a few times to reduce the adhesive.
Set the tape loops on the outside surface of the wrap, one on each side.



Set the wrap, printed side down on scrap cardboard for a shot of adhesive. The tape holds the wrap down close to the backing board preventing any spray from getting under and on the finished side.
I use the 3M 77 adhesive spray.
The 3M 45 is too light a tack, the 90 formula is too strong.

ASP D Region Tomahawk Build, Part 15, Fin Plate Forming and Adhesion

Bend the long (already embossed) sides over a straight edge.
You should be able to set the metal edge of a ruler into the embossed line. Press up with your fingertips. Crease the entire length of the fold.









You'll have to go back and curve the bottom again after folding the sides.

Here's the underside and outside of the fin plates.
Set them into the space between the fins to be sure you have the curve and folds right. Re-form them if needed.


Set them on a scrap piece of cardboard for adhesive spray. Here they are set on masking tape with the sticky side up.

The backside of the plates were lightly sprayed with 3M 77 spray.

3M 90 Spray Adhesive on Estes Vacuform Wraps? TIP

From a Model Rocketry Fanatics Facebook Post by Justin Farley:

Justin Farley: "FYI: 3M 90 spray adhesive works great at melting vacuform wraps if that is your desired goal. It is pretty bad all the way around, fortunately the really Freddy Krugered part will be on side with launch lugs. It still looks bad, this build was going too smoothly."

Lee Reep: "There is a build thread on TRF on the new Estes Little Joe II that shows using 3M 90. James Duffy points out it goes on like a spidery web. By any chance did you put it on and try to get a uniform (and therefore heavy) coat of adhesive?"

Justin Farley: "Perhaps it is that Estes is using ABS instead of polystyrene now, but I think I probably applied way too much. Which is easy to do given how it comes out in a stream as opposed to a mist like the 77 does." 

My take: There are three different strengths of 3M Spray Adhesives. 

"45" Economy Grade, bonds paper, cardboard, photos.

"77" Medium Grade, dries quick and clear, Bonds to foil, paper, cardboard, fabric, plastic, metal and more.

"90" Industrial Strength, bonds laminates, kick plates, poly and plastic lettering.

The vacu-form wraps used on the Saturn V kit feel different than the wraps from the Little Joe II. Estes doesn't go into enough detail as to which plastic adhesives to use in their kits.

For the vacuform wraps I have had very good results using the 3M Super 77. I felt the 90 adhesive might be more strength than might be needed. Some have had good results using it, but you don't want to apply too much! Practice on edge scraps, never on the final kit build parts.

Some areas on vacuform parts are thinner than others. The solvent in the 3M 90 may have melted those thinner areas.

Don't use tube cement to glue any of the Little Joe II plastic parts together (capsule, tower and details). Plastic model cement is not what it used to be. I used Plastruct Plastic Weld with very good results.

Estes Apollo Little Joe II Build, Part 7, Wrap Adhesion

Small rolls of tape with the sticky side out held the wrap onto a piece of cardboard for spraying.

I don't mean to insult anybody's intelligence, but be sure you have the underside of the wrap facing up before using the spray adhesive. It could happen and you'd never be able to remove the adhesive from the corrugations.

James Duffy explained that the High Strength 90 adhesive sprayed with a splatter, looking like webbing. The Super 77 I used splattered a bit but the coat looked smooth.
I chose to spray both surfaces, the tube and the back of the wrap. I didn't wait long to apply the wrap. It did stick very well but did allow it to be lifted and re-aligned.
The end joint seam almost met up. The thickness of the spray adhesive did increase the outside diameter a bit. Not bad, but not a perfect butt-joint end. It'll be covered by the long tunnel anyway.

Everything was down but after a while the ends started to lift. I'll have to get a small drop on CA glue under the wrap ends and burnish.

Estes Apollo Little Joe II Build, Part 6, Wrap Adhesion

On the Rocketry Forum build thread James Duffy used the 3M High Strength 90 adhesive, George Gassaway used the 3m Type 77 adhesive.
I wanted to make the right choice, you only have one shot to get the wrap on.
I had a can of the 3M General Purpose 45 adhesive. This product is for lighter use like photo adhesion and craft products, not for rocketry.
I went to the 3M website to get more information. The website showed the Type 90 adhesive used in construction, one picture showing counter top adhesion. I wanted something that might allow a lift and re-position before it was stuck for good. I picked up a can of Scotch Super 77, the mid grade adhesive.

The can instructions lead you to think you've only got 10 seconds to position the glued pieces. Reading it again you see it says 10 seconds to 30 minutes. I hope that means you have 30 minutes to pull up the wrap and reposition it before the final grab.
That's what I hate about "one shots". You won't know until you're in the middle of it, working against the clock.

I should note, this can did not look like the products pictured in the Rocketry Forum build thread. This can was from Michael's Crafts and was labeled "Scotch". Look to the right of the circle and there is a 3M logo.

To mask off the body tube, I did a simple copy paper wrap above the upper card stock strip. Another piece of paper was rolled inside the rear of the tube to mask the inside.